ADS1235 - 24-bit, 7.2kSPS, 5-ch delta-sigma ADC with PGA and AC excitation for low-noise bridge sensors

The ADS1235 is a precision, 7200-SPS, delta-sigma (ΔΣ) analog-to-digital converter (ADC)with an integrated programmable gain amplifier (PGA). This device also includes diagnostic featuressuch as PGA overrange and reference monitors. The ADC provides high-accuracy, zero-drift conversiondata for high-precision equipment, including weigh scales, strain gauges, and resistive pressuresensors.

The ADC has signal and reference multiplexers that support three differential signalinputs and two reference inputs. The ADC also includes a low-noise PGA that provides gains of 1,64, and 128. The ADC also has a 24-bit ΔΣ modulator and programmable digital filter.

The high-impedance inputs (1 GΩ) of the PGA reduce measurement error that is caused bysensor loading.

The ADC supports ac-bridge excitation to remove the drift errors from the sensor wiring.The ADC provides the clock control signals for the ac-excitation operation.

The flexible digital filter is programmable for single-cycle settled conversions, andprovides 50-Hz and 60-Hz line cycle rejection at the same time.

The ADS1235 is available in a 5-mm × 5-mm QFN package, and is specified across the –40°Cto +125°C temperature range.

• 24-Bit, High-Precision ADC
  • 120,000 Noise-Free Counts
    (10-mV Input, 10 SPS)
  • Offset Drift: 1 nV/°C
  • Gain Drift: 0.5 ppm/°C
• Three Differential or Five Single-Ended Inputs
• Two Reference Inputs
• Wide Input Voltage Range: ±7 mV to ±5 V
• Low-Noise PGA, Gain: 1, 64, and 128
• Data Rate: 2.5 SPS to 7200 SPS
• AC- or DC-Bridge Excitation Option
• Chop Mode for Zero Drift Operation
• Simultaneous 50-Hz and 60-Hz Rejection Mode
• Single-Cycle Settling Mode
• Missing Reference Input Monitor
• Signal Overrange Monitor
• Temperature Sensor
• Cyclic Redundancy Check (CRC)
• 5-V or ±2.5-V Power Supply

All trademarks are the property of their respective owners.